Scaffolding structure



w. w. SCHUMACHER 2,708,606

VSCIAFFOLDING STRUCTURE Filed March 25, 1950 May 1 7, 955

INVENTOR.

w/u/nm w. sewumnrl/zk 2a BY United States Patent 2,708,606 SCAFFOLDING STRUCTURE William W. Schumacher, Detroit, Mich., assignor to Miller Stamping Company, Detroit, Mich., a partnership of Michigan Application March 25, 1950, Serial No. 151,963

6 Claims. (Cl. 304-40) This invention relates to a scaffolding structure and particularly to an interlock joint for cross-stays of a metal temporary scaffold.

In recent years, it has become common for scaffolding companies to rent out metal framework which can be so interlocked and joined together that temporary scaffolding can be raised outside or inside a building to permit construction and repair work to be done. Some of these structures are joined together by ordinary nuts and bolts or wing nuts. Others have been joined together by special locks which are intended to save time in the assembly and disassembly of the parts.

It is an object of the present invention to provide a special locking device which permits swift assembly of parts and similarly facilitates dismantling while eflecting complete safety during the use.

Briefly, this is accomplished by a special locking flange which co-operates with an adjacent pin to give a two point location for a cross-member and a third element on the locking flange which is shiftable from a stable open position to a locked position holding the cross-stay until intentionally released.

Details of the construction and other objects and features will be found in the following description and claims.

' Drawings accompany the specification, and the various views thereof may be briefly described as:

Figure 1, a perspective view showing a portion of a scaffolding assembly.

Figure 2, a detail view of one edge of the locking unit.

Figure 3, a view taken on one side of Figure 2 showing the additional details of the locking construction.

Figure 4, a sectional view on line 4-4 of Figure 3.

Figure 5, a sectional view on line 55 of Figure 3.

Figure 6, a partial elevation of a part of Figure 3.

Referring to the drawings, the usual manner of constructing the scaffolding consists in using a plurality of end frames E having vertical tubular members 10, horizontal struts 12 and 14, and diagonal braces 16 and 18. These end frames E are joined by removable cross braces or stays 20 which co-operate with fastening means on the upright members 10.

A latching or connecting plate 22 at the end of member 20, shown particularly in Figures 2 and 4, is apertured at 24 to receive a pin 26 rigidly mounted on pipe 10. At the top edge of plate 22 a notch 28 is formed to engage the bottom edge of a locking plate 32 when at right angles thereto. Plate 32 is attached rigidly to and extends radially outward from the pipe 10.

A shoulder 34 projects downwardly from lock plate 32 to serve as a stop for latch plate 22 and similarly an enlargement 36 on stud 26 serves as a stop for plate 22. Thus, when latch plate 22 on the cross member 20 is assembled with respect to the stud 26 and the lock plate 32, there is a two-point interlock which gives a rigid connection.

The locking means for holding plate 22 in position consists of an elongate U-shaped gravity plate 40 which "ice is mounted by a pin 42 in a slot 44 in plate 32. As viewed in Figures 3 and 6, it will be seen that the plate 32 has an outer edge which slants downwardly from the top in two straight sections 46 and 48. The slot 44 carries out this general relation to the edges as shown best in Figure 6.

Pin 42 slides in this slot 44 to permit an upward movement of the gravity plate 40. Due to the location of the hole 50 in plate 40 through which the pin 42 passes, it

will be seen that the gravity plate is positioned definitely with respect to plate 32. The plate is U-shaped and the two sides straddle the plate 32 while the bottom end is split and widened to provide two legs 52 which will pass on either side of the pin 26 and bear against plate 22 when positioned as shown in the full lines of Figures 2 and 3.

The back portion 54 which connects the sides of the gravity plate at one end under these circumstances lies against the surface 46 of plate 32, thus preventing a pivotal movement and holding the legs 52 in position. When the gravity plate is lifted from the lock position, however, the upper corner of it indicated at 56 will pass through an opening in the back and the plate 40 may then pivot so a small up-turned tail 58 will rest on the top of plate 32. In this position the legs 52 have swung outwardly so that it is a simple matter to release plate 22 from its' locked position.

If desired, small serrations or ribs 60 can be formed in the back of slot 44 to aflord frictional resistance against the pin 42 to prevent its vibrating upward.

Under usual circumstances, the weight of the gravity plate and pin will be ample to hold the parts in locked position, unless there is an intentional lifting of the plate 40.. Directly above the pin 42 a supplemental hole 62 is provided for the use of a cotter key or other pin 64 to lock the gravity plate in position in installations where malicious dismantling might take place.

It will thus be seen that a simple manual movement will release or engage the locking means which otherwise is in a stable locked position. With this arrangement any unskilled workman may assemble the scaffolding rigidly and safely, and it is easy to tell at a glance when all of the locking parts are in proper position. In addition, a two-point lock on plate 22 is obtained by a simple and inexpensive construction, thus affording rigidity to the cross-stays 20 which would not be obtained by a single fastening point.

What I claim is;

l. A detachable connection for separable structural members of a portable scattold which comprises first and second members to be attached together, a lock plate aflixed to the first member, a latch plate aflixed to the second member, means at the edges of said plates to engage when the plates are in a position edge to edge at right angles to each other each in a vertical plane,

, means on said first member and means on said latch plate to interengage when said plates are in the above described position, and releasable lock means movable on said lock plate to a lock position to overlie and hold said latch plate in said position, said locking means comprising an elongate member, means slidably and pivotally associating said elongate member on said lock plate wherein it is movable to a lock position where one end blocks outward disengaging movement of the latch plate, and means on said elongate member overlying a portion of the lock plate to inhibit the pivoted movement of the elongate member when in lock position. i

2. A detachable connection for separable structural members of a portable scaffold which comprises first and second members to be attached together, a lock plate aflixed to the first member, a latch plate aflixed to the second member, means at the edges of said plates to engage when the plates are in a position edge to edge at right angles to each other, means on said first member and means on said latch plate to interengage when said plates are in the above described position, and releasable lock means on said lock plate to hold said latch plate in said position, said locking means comprising an elongate .member,-means connecting said member to said lock plate for slidable and pivotal movement comprising a pin and slot wherein said member is movable to a lock position blocking outward release movement of said latch plate, and means integral with said elongate member co-operating with the lock plate to prevent pivotal movement when in lock position.

3. A detachable connection for separable structural members of a portable scafiold which comprises first and second .members to be attached together, a lock plate affixed to the first member, a latch plate affixed to the second member, means at the edges of said plates to engage when the plates are in a position edge to edge at right angles to each other, means on said first member and means on said latch plate to inter-engage when said plates are in the above described position each in a vertical plane, and releasable lock means on said lockplate to hold said latch plate in said position, said locking means comprising a U-shaped elongate member capping the outer edge of said lock plate and slidable up and down on said plate, means on said elongate member and means on said lock plate to associate the two for relative sliding and pivotal movement, means to limit the sliding movement and means to prevent outward pivotal movement of the lower end of said elongate member when in its down position said lower end in said position overlying the latch plate to block disengagement thereof.

4. A connection for structural members as defined in claim 5 in which a spacing shoulder is formed on said lock plate and said pin adjacent said first member to provide positive locating means for two points on said latch plate.

5. A detachable connection for separable structural members of a portable scaffold which comprises a first member to be positioned vertically in the scafiold, a second member to serve as a connector to attach to said first member at an angle thereto, a lock plate in a vertical plane afiixed to and extending outwardly from said first member, a latch plate in a vertical plane affixed to said second member, a notch in the latch plate to engage the lower edge of the lock plate when the plates are at right angles to each other, a pin on said first member extending v horizontally through an aperture in said lock plate when said plates are so positioned, a releasable locking bar on said lock plate, a pin-slot connection between said bar and lock plate to permit vertical movement of said bar on said plate, means on said bar extending over the edge of said lock plate to block pivotal movement of said bar until raised on said plate, said bar in its down position extending over said horizontal pin to block dislodgment of said latch plate.

6 in a detachable scaffolding structure of separable members wherein a projecting pin on one member passes through an apertured second member, a means for locking the second member on the pin which comprises a plate mounted adjacent said pin, and a locking bar on said plate movable to a lock position to overlie said pin comprising an elongate member of U-shaped cross-section overlying and slidable on the outer edge of said lock plate, a pin pivotally mounting said bar on said plate transfixing the sides of said elongate member movable in a slot in said lock plate, and a bight portion at the top of said elongate member to engage the edge of said lock plate to block pivotal movement of said elongate member while in lock position.

References Cited in the file of this patent UNITED STATES PATENTS 249,508 Douns Nov. 15, 1881 427,180 MacLaurin May 6, 1890 1,579,854 Besse Apr. 6, 1926 2,236,439 McKenna Nov. 25, 1941 2,256,678 Kern Sept. 23, 1941 2,449,251 Rogoff Sept. 14, 1948 2,483,862 Weisz Oct. 4, 1949 2,561,938 Meng et al. July 24, .1951 2,620,237 Kirkpatrick Dec. 2, 1952 

